1. Field of the Invention
This invention relates to a system of products which are used to remove herniated or protruding disc material from the human body back using a surgical technique which involves making a very small incision through the skin into the lower back, endoscopic percutaneous discectomy. This typical embodiment is a specific example of a system of products which permit visualization into an area of the human body which is not a normal body cavity, and then under direct visual control, removal of abnormal or pathological structures from that portion of the body.
2. Description of Prior Art
Normal method for surgical treatment of a severely bulging or herniated disc in the lower back is massive open surgery in which an 8-10 inch incision in the skin is made, followed by dissection down through muscles and ligaments to access the actual disc, that is only 3-5 cubic centimeters in volume. Pain, suffering, and extended time to complete recovery is caused much more by the 8-10 inch surgical incision or wound. Time for return to a normal lifestyle is 4-6 months following this operation, according to published medical papers. National cost for this operation, including both cost of actual medical care and workman's compensation from the extended time off from work is about $3 billion annually.
A more recently employed operation involves "microsurgery" in which only a 2-3 inch skin incision is made, to reduce pain, time in the hospital immediately following surgery, and time for return to normal. Within the last 2-3 years, percutaneous discectomy, a surgical procedure in which tubes are placed through the skin and into the disc, and a portion of the disc is removed, using manual instruments or a pneumatically powered cutting device, has been used by a limited number of pyhsicians. The theory behind the percutaneous discectomy procedure is, if disc material is removed, pressure within the disc will be reduced and the herniation from the disc will retract into the main portion of the disc.
Success rate for percutaneous discectomy has only been about 70%, much lower than for the major, 8-10 inch surgical operation, and a cause and effect relationship for failure of percutaneous discectomy has not been proven. But since percutaneous discectomy, an operation that can be performed on an outpatient basis, involves much less pain, suffering, recovery time, and cost, it has become more popular with surgeons and patients, and a lower success rate, 70%, is an acceptible complication. If initial percutaneous discectomy is unsuccessful, reoperation or the open surgical procedure is performed.
This has benefitted the nation as a whole, given the explosive increase in cost of medical care which this country is currently experiencing. Since disabling back injury is increasing faster than any other injury, since compensable back injuries affect 2% of all employees each year, and since 24% of all lost time industrial accidents are back related, according to Federal government statistics, improved devices used to perform percutaneous discectomy are needed, to provide a higher success rate and further reduce the cost in treating this specific medical problem.
Prior art involves open tubes placed into the disc, through which manually operated stainless steel surgical instruments are passed. These instruments bite off chunks of the disc material which are then enclosed in the instrument. The instrument must be removed from the back to clean out the material and then be reinserted into the back, repeating this technique many times to excise a sufficient enough volume of disc material to have positive effect.
Additional prior art is a system of devices for percutaneous discectomy involving open tubes placed into the disc, through which a pneumatically powered cutting device is passed. This product also aspirates excised material from the disc, and collects it in a volume measuring reservoir.
Although these devices effectively remove some disc material, lack of visual control during the removal process and more importantly lack of visual control to ascertain completeness of the excision dictates the operating physician must rely on measure of volume of excised material to assume that enough has been removed to produce a positive effect and relieve the symptoms of the patient.
Biomechanical studies suggest that removal of disc material from the anterior portion of the disc space, which is dictated by the design of the prior art, produces a far less stable post-surgery lower back, and may be a contributing factor to a high failure rate for the prior art.
Because of size of prior art, pneumatically powered cutting devices, removal of adequate volume of disc material is a tedious process for the surgeon, and extends time of surgery, and as a result cost of medical care. Use of prior art products leaves a dead space in the back which immediately fills with fluid and eventually loose connective tissue. Preferrably, bone should fill this space, as is done during the major, open surgical procedure, when insertion of bone graft material to create what is known as a spinal fusion is one of the final phases of the procedure.
Related prior art involves small diameter, optical medical telescopes which have been used for orthopaedic arthroscopy for several year, and other surgical procedures for decades. Arthroscopes have a shape and size that make them beneficial in performing the arthroscopic technique, but not effective for performing percutaneous discectomy.
Additonal related prior art is fiber optic light illuminators that are used for medical, endoscopic surgical procedures in general and for orthopaedic arthroscopy in particular. These light sources do not provide the light intensity to properly illuminate the disc space, and produce clear images with the medical video camera system that is used in conjuction with the percutaneous discectomy scope.
Additional related prior art is a peristaltic pump used to instill fluid, usually normal saline, into a body cavity to expand its volume, and provide a clear liquid medium to view the body cavity using a generic type of endoscope. This instilled fluid may be removed from the body cavity either through the endoscope or through a separate outflow conduit, usually by applying active suction to the conduit and connecting PVC tubing, the suction being generated by some external aspirating pump. Precise control of rate of inflow is not achieved with prior art instilling pumps, and coordination of volume of inflow to volume of aspiration, through electronic controls is not characteristic of these forms of prior art.
Related prior art are machines which function independently including light source illuminators, peristaltic pumps, pneumatically powered tissue resectors, suction machines, and electromechanical tissue resectors used for surgical procedures other than indicated in this patent application.
As indicated above, a system of devices for percutaneous discectomy is a typical embodiment of a generic system of energy form generating and energy form transmitting surgical devices which function in an integrated, coordinated manner to provide illumination, visualization, tissue resection, and transport of resected tissue, from an area of the human body which is not normally a body cavity, With the aspect of the system that is placed partially within the human body containing all energy forms within the same physical structure, and with the energy generating or energy transforming aspect of the system contained in the same chasis.
Prior art for the generic system of energy form generating and energy form transmitting surgical devices are energy form generators that produce light to illuminate a body cavity such as the stomach, lung, bladder, or abdomen, energy form generators that produce electrical cutting energy used through an energy transporting device to remove abnormal tissue such as from the stomach, intestine, or urinary tract, electromechanical energy cutting devices used through an energy transporting device to remove abnormal tissue such as from the knee, shoulder, or blood vessel system, energy form generators that produce laser cutting energy used through an energy transporting device to remove abnormal tissue such as from the intestine, blood vessel system, cranium, abdomen, or lung.
Additional related prior art is indicated above, specifically endoscopes which are used to visualize within body cavities, and pumps and aspiratiang devices which are used to inflow and aspirated fluids into and out of these body cavities.
Prior art devices are not designed to coordinate all four functions identified in this invention, illumination, visualization, energy form generation and transmission, and transport medium inflow and outflow, within the same operating console, and within the same device that is placed partially within the human body, but not into a normal body cavity. Therefore, these devices do not work as efficiently together, extend operating time which increases cost of medical care. Energy form generators and transporters being separate machines, their total cost is greater ands they require more effort by personnel to set up and maintain, which also increases cost of medical care. Because several separate devices must be placed within the human body with prior art devices, multiple surgical incisions are required which increases recovery time, pain and suffering for the patient.